RESUMO
The increment of eryptosis in lead-exposed workers has been associated with oxidative stress, having as the main mediator [Ca2+]i. However, other molecules could participate as signals, such as PLA2 and SMase, which have been proposed to increase PGE2 and ceramides, both involved in the increment of PS externalization due to osmotic stress. To study the role of these enzymes in lead intoxication, we studied 30 lead exposed workers and 27 non-lead exposed individuals. We found, compared to non-exposed subjects, lead intoxication characterized by high blood lead concentration (medianâ¯=â¯39.1⯵g/dL), and low δ-ALAD activity (medianâ¯=â¯348â¯nmol of porphobilinogen/h/mL); oxidative stress with high lipid peroxidation (medianâ¯=â¯1.31â¯nmol of malondialdehyde/mL) and low TAC (medianâ¯=â¯370â¯mM Trolox equivalents); a higher enzymatic activity of PLA2 (medianâ¯=â¯518 AFU/mg) and SMase (medianâ¯=â¯706 AFU/mg) and higher eryptosis (medianâ¯=â¯0.92% PS externalization). Correlation and conditional probability analyses permit to associate oxidative stress and eryptosis with high PLA2 activity. However, high SMase activity was only associated with PLA2 activity. The role of these enzymes in the signal path to eryptosis induced by oxidative stress in lead-exposed workers is discussed.